Reports
The water resources of Anne Arundel County
1949, Bennion, V.R. and Brookhart, J.W.
Bulletin 5
Abstract
This report gives the basic data obtained during an investigation of the ground-water resources of Anne Arundel County, Maryland. Anne Arundel County is in the central part of Maryland adjoining the western shore of Chesapeake Bay. The county may be considered to lie wholly within the Coastal Plain, although the area near the northwestern edge of the county contains crystalline rocks that characterize the Piedmont Plateau. The Coastal Plain formations in Anne Arundel County are of Lower and Upper Cretaceous, Eocene, Miocene, and Pleistocene age, and all are sediments consisting chiefly of sand, gravel and clay. All the formations, except the Pleistocene deposits, strike northeast and dip gently to the southeast. The Pleistocene deposits are essentially flat-lying and form terraces.
The costal plain sediments contain several water-bearing formations of which the Patuxent, Patapsco, Raritan, Magothy, and Aquia are the most important. About 35,000,000 gallons of water a day are pumped from the Patuxent formation in the Baltimore area, which adjoins Anne Arundel County on the north; however, this formation is not utilized extensively in Anne Arundel County because, in general, it lies at a relatively great depth. The Patapsco formation probably is utilized more than any other formation for ground-water supplies in the County. It yields as much as 1,000 gallons a minute to large-diameter wells in the Annapolis area. The Raritan formation yields adequate supplies of water for domestic and farm use and probably furnishes a part of the water for the Naval establishments and public supply at Annapolis. The Magothy formation yields as much as 1,000 gallons a minute to wells in the Annapolis area. However, a part of the water from these wells may be derived from the Raritan formation. It also yields adequate supplies of water to many domestic and farm wells. The Aquia formation is present in the southern part of the County where it yields adequate supplies of water for domestic and farm use. One well ending in the Aquia formation yields about 150 gallons a minute.
All of the aquifers yield water of a quality that is satisfactory for most uses, but, in a large part of the area, treatment is required for removal of iron.
Water-level measurements obtained during a 3½-year period show no appreciable change. Available hydrologic data indicate that pumpage from the important aquifers could be increased considerably without serious depletion of the supply.
